Heat Pump Parts

If you have searched the web for heat pump parts....chances are you are a little frustrated.

Most industrial supply houses carry a few parts, or maybe a few dozen parts.

But there are thousands of parts in the heat pump industry to choose from, depending on which heat pump you have.

......Chances of finding the exact part you are looking for is very slim.

Here we have done the work for you.  Below you will find the most likely location for finding the right part!

What Heat Pump Parts Are You Looking For?

The following parts are discussed in detail below:

  • Bracket (Condensing Unit Support)
  • Capacitor
  • Check Valve
  • Control Board
  • Compressor
  • Condenser Fan and Condenser Fan Motor
  • Contactor or Relay
  • Crankcase Heater and Crankcase Heater Thermostat
  • Control Board and Defrost Thermostat
  • Expansion Valve
  • Filter Drier
  • High Pressure Switch or Low Pressure Switch
  • Reversing Valve and Reversing Valve Solenoid
  • Suction Accumulator
  • Transformer

Bracket (Mini Split Outdoor Unit Support)

There are a number of options available when deciding to purchase a wall mount bracket for mini split heat pumps.  Keep the following in mind:

  • When purchasing a wall mount bracket, be sure that you purchase a "universal" type bracket.  Unless the bracket you purchase is made for your exact model.
  • Be sure the bracket size and weight capacity fits your unit.
  • Select a bracket that will not rust easily this could be stainless steel (expensive) or a polymer based bracket.

Do you need a heat pump or condensing unit mounting bracket?

Upon product review, here is our recommended bracket that has a universal design which allows any model to be installed:


Most heat pumps have two types of capacitors; start capacitors and run capacitors.  A bad capacitor is one the most common reasons for heat pump trouble.  You can usually tell that a capacitor is bad if the top is bulged outward.  It is important to test your capacitor with a multimeter to determine if that is the cause of your problem.

It is usually best to purchase the capacitor from a local suppler for heat pump parts, in order to ensure that you get the correct, quality capacitor.  Below are a few nationwide suppliers that you may located in your area:

  • Johnstone Supply
  • United Refrigeration Supply

Check Valve

A check valve is a very important device in the refrigerant circuit.  

It prevents refrigerant from flowing in the wrong direction.  Depending on the location, refrigerant which flows in the opposite direction can result in very serious damage to the heat pump.

Most refrigerant check valves are either spring or magnetic type valves.  The most common check valve manufacturers are:

  • Danfoss
  • Mueller Industries
  • Sporlan Valve (also known as Parker Valve)
  • Emerson Climate Technologies
  • Henry Technologies
  • Superior Refrigeration

It is important that you purchase the correct replacement check valve.  Each style and manufacturer has different pressure drop ratings.  Installing a different check valve in a system can significantly affect the operation of the heat pump.  

For this reason, we recommend that you go directly to your local manufacturer dealer for purchase of these heat pump parts.

Control Board

Your heat pump comes with a control circuit board that operates the heat pump in a safe and efficient manner.  In our opinion, this is one of the most important of all heat pump parts.

For this reason, if you are going to buy it online, be absolutely sure that you purchase the correct part number!

Otherwise, it is best to contact the manufacturer's dealer for these heat pump parts.


A compressor is the heart of a heat pump.

Many questions arise when:

  • You are looking to buy a new compressor
  • You are worried that the compressor may be going bad
  • .....Or just looking for general information regarding your compressor.

Click on the link for a Frequently Asked Questions guide devoted completely to the heat pump compressor.

Condenser Fan or Condenser Fan Motor

Usually a bad condenser fan is really a bad condenser fan motor.

But if you need a new condenser fan blade, it is best to purchase this from the local dealer for your heat pump manufacturer.  A replacement blade usually is not an exact replacement.

However, there are many online options for purchasing a new condenser fan motor.  

You can easily purchase an off-brand motor that matches the existing motor and performs equally well.  

Below are a few good, online sources.  Some of the sources below are perfect for matching motor specs and other sources are perfect for matching the motor manufacturer:

Important: make sure that the motor you purchase is specified as a "condenser fan motor".

  • EMotorStore.com: just search for your fan manufacturer and part number.
  • Global Industrial has a good selection of US Motors as a decent price. Also if you have some experience with selecting motors and are interested in picking up the motor at a local supply house, Grainger may be your best bet.

Contactor or Relay

These heat pump parts can be purchased at any electrical supply warehouse, as long as the specifications match the original.

Be sure that the following specifications match the original:

  • Coil voltage
  • Number and style of poles
  • Contact rating at the operating voltage is at least the original
  • Torque rating

Here are a few recommended online locations for purchasing contactors and relays:

  • Kele: May not be the cheapest option, but they have a great selection and great service.
  • FactoryMation.com: Usually a very cost effective option.

Crankcase Heater and Crankcase Heater Thermostat

The crankcase heater is an electric resistance heating element which is inserted into the crankcase of the compressor.  The purpose is to keep the oil in the compressor crankcase warm.

Oil in a refrigeration system is selected to operate at higher than ambient temperatures, usually between 90 - 230 F.

So when a compressor first starts after being off for a long period of time, the oil temperature is equal to its surroundings.

If it is 65 F outside, the oil is 65 F.  This presents a problem.....

When the oil is colder than its designed operation temperature, it becomes very viscous, or thick.

A cold start with thick oil can, over time, damage the compressor.

So, if the crankcase heater or thermostat needs to be replaced, be sure to purchase the exact type or an exact replacement as specified by the manufacturer.

For this reason I recommend always purchasing the crankcase heater and thermostat from the manufacturer's dealer for these heat pump parts.

Defrost Control Board and Defrost Thermostat

When a heat pump is operating at low outdoor temperatures (less than 45 F), the outdoor air coil could potentially begin to freeze.

This can cause severe damage to the heat pump.

In order to avoid this damage, heat pumps include a coil defrost package.  At specific intervals, hot gas is forced into the outdoor coil resulting in "defrosting" the coil.

Unfortunately, this defrost option often causes many problems.  If the heat pump defrost is not operating correctly, the result can be:

  • Very high utility bills
  • Insufficient heating

For this reason, if the defrost control board or defrost thermostat is bad I do not recommend trying to find this at a discount online retailer.

The pain of selecting a slightly less expensive, but wrong part can be very severe.

Please.....go to your local manufacturer's dealer for these heat pump parts!

Expansion Valve

The expansion valve allows the heat pump system to operate in a controlled manner and keeps the compressor safe from liquid flooding.

Even the slightest change in the expansion valve can have a detrimental effect on the system and its efficiency.

For this reason, always contact the manufacturer's dealer to ensure that you purchase the correct expansion valve!

Filter Drier

A filter drier does as described.....

It "filters" out any non-condensibles in the heat pump system.

And....it "dries" or pulls out moisture from the refrigerant.

Usually you can replace a liquid line filter drier as long as you ensure the following:

  • Use the same pipe size connections as the original.
  • Use the same style filter drier to ensure a similar pressure drop as the original.

Below are a few options as to where you can purchase a filter drier:

  • Local manufacturer's dealer
  • Refrigeration supply house for heat pump parts (such as Johnstone Supply and United Refrigeration)
  • Grainger: Good online selection for filter driers.

High Pressure Switch or Low Pressure Switch

A high pressure switch exists between the discharge of the compressor and the inlet of the condenser.  The purpose of this switch is to ensure that the pressure does not exceed the maximum allowable by design.

A low pressure switch exists between the outlet of the evaporator and the inlet of the compressor.  Again, the purpose of this switch is to ensure that the pressure does not drop below the minimum allowable by design.

Both safety switches are very important.  Many problems that can exist in a heat pump is first indicative of abnormal pressures.

Are you looking to purchase a high or low pressure switch?

Because of the important of this safety switch and the small differences between one switch and another, we recommend contacting your manufacturer's dealer for an exact replacement.

Only those very experienced in these safety switches can venture outside the standard replacement.

.....And the cost difference should not be significant when purchasing it from a local dealer of heat pump parts.

Reversing Valve and Reversing Valve Solenoid

A reversing valve is a four port valve which allows the heat pump to switch from cooling mode to heating mode.

It re-routes the refrigerant to opposite heat exchangers (outdoor air coil to indoor air coil and vice versa).  So it is one of the most important of all heat pump parts.

Reversing valves are common maintenance items and are not specialized for each heat pump. As long as the solenoid voltage matches that of the existing reversing valve solenoid, it should work.

The following online retailers contain a good assortment of reversing valves (don't forget to buy the solenoid, as it usually comes separate):

  • PexSupply.com: Contains a good supply at a decent price.
  • Grainger.com: Price may not be ideal, but also contains a good supply and usually has very good stock.

....And when you go to braze the valve, be very careful as the port seals are sensitive to heat (could melt).

Suction Accumulator

Replacing a suction accumulator is very rare.  Often it is used as an add-on to existing heat pumps that do not have suction accumulators.

The purpose of a suction accumulator is to trap liquid refrigerant that escapes past the evaporator.  Sometimes due to fluctuating conditions (especially as start-up), the liquid refrigerant is not completely boiled out in the evaporator.

Persistent liquid problems will sooner or later damage the compressor.

Below you will find a specific suction accumulator manufacturer.  They will sell directly to the consumer.  This is probably your cheapest, yet most quality-driven option.

However, do not install a suction accumulator into a heat pump system unless you have experience selected and designing systems with suction accumulators.  Just adding a suction accumulator to a system with liquid problems will not solve your problem!  It merely acts as a buffer for small amounts of random liquid, especially at start-up.


A transformer is a transformer.

Just because it is in a heat pump system does not make transformers special heat pump parts.  So unless you are concerned with warranty expiration, you can purchase an exact replacement from another supplier.

When selecting a new transformer it is very important to match the following to the original transformer:

  • Primary voltage (incoming voltage)
  • Secondary voltage (outgoing voltage)
  • Capacity in VA (volt-amps) or kVA (kilovolt-amps)
  • Number of poles and taps

Here are some great online resources for control transformers:

  • ´╗┐Kele.com: May not be the cheapest option, but they have a great selection and great service.
  • FactoryMation.com: Usually a very cost effective option.

Click here for a Johnstone Supply catalog of heat pump parts if you don't find what you are looking for here.

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